【作者】 陈浩；

【导师】 吕国安；

【作者基本信息】 华中农业大学 ， 土壤学， 2003， 硕士

【摘要】 我国鄂东南红壤丘陵地区（咸宁地区）由于降水分配极不均匀，水利设施不健全，土壤侵蚀严重。土壤水分作为影响土壤肥力和作物生长的重要因素，在很大程度影响了土壤侵蚀。本文研究了该地区不同母质发育的不同侵蚀程度红壤的水分特性，并首次对红壤结构体的水分特性进行了研究，提出了测定结构体水分特性的方法，同时通过野外径流小区和室内冲蚀槽人工模拟降雨试验，研究了不同母质发育的不同侵蚀程度红壤的渗漏性能。主要得出如下结果： 对于不同母质发育的红壤，Q₂发育的红壤的持水量大于花岗岩发育红壤的持水量。对于相同母质发育的红壤，在低吸力阶段，轻度侵蚀、中度侵蚀、重度侵蚀土壤的持水量相差不大；而在高吸力阶段，重并侵蚀土壤的持水量＞中度侵蚀土攘的持水量＞重度侵蚀土壤的持水量。 供试土壤低吸力阶段的供水能力远大于高吸力段供水能力。对于不同母质发育的红壤，在低吸力阶段，Q₂发育红壤的供水能力大于花岗岩发育红壤的供水能力，而在高吸力阶段，不同母质发育红壤的供水差异很小；对于同种母质而言，不论是低吸力段还是高吸力段，土壤的供水能力都是轻度侵蚀＞中度侵蚀＞重度侵蚀。 不同大小结构体的容重随结构体大小的减小而明显增大，同时，总孔隙度随着结构体大小的减小而减小。不同大小结构体在4-33Kpa吸力阶段的含水量和通气孔隙随着结构体大小减小而减小。 Q₂发育红壤的饱和导水率小于花岗岩发育红壤的饱和导水率，轻度侵蚀的饱和导水率＞中度侵蚀的饱和导水率＞重度侵蚀的饱和导水率。在低水分饱和度阶段，Q₂发育的红壤的水分扩散速率与花岗岩发育红壤的水分扩散速率相差不大，而在高土壤水分饱和度阶段，Q₂发育的轻度侵蚀和中度侵蚀的水分扩散速率比花岗岩发育的轻度侵蚀和中度侵蚀的水分扩散速率大。 在相同的降雨条件下，轻度侵蚀的渗漏速度大于中度侵蚀和重度侵蚀，雨前含水量、容重、坡面位置、雨强都影响土壤的渗漏。加盖筛网，可以减小雨滴动能，增加土壤的渗漏，减少径流。雨滴动能对于轻度侵蚀土壤的影响大于对重度侵蚀土壤的影响。 降雨后供试土壤总含水量下降，同时土壤重力水明显减小，雨后的有效水比雨前大，无效水比雨前小，迟效水降雨前后无明显变化规律。降雨后土壤的总孔隙度下降，通气孔隙下降较明显，同时速效孔隙和迟效孔隙增多。雨后土壤饱和导水率明显小于雨前，坡下饱和导水率减少的幅度大于坡中和坡上。更多还原

【Abstract】 In the red region of the southeast of Hubei province , the end of the summer and autumn are the drought season , soil water is very important for crop production and erosion at that time. My research include the water characteristics of several kinds of erosion soil using pressure membrane extractor and the percolation characteristics using simulator rainfall in the fields and in the lab.The water-holding capacity of red soil derived from Q2 was higher than the red soil derived from Granite. In the lower soil suction range , the different among the water-holding capacity of weekly and moderate and Intensely erosive red-soil derived from Q2 and Granite was not widely. In the higher soil suction range the different was widely. That of the intensely erosive red-soil was higher than the moderate and intensely erosive red-soil.The water-supply capacity of red soil in the lower soil suction range was higher than that of in the higher soil suction range. In the lower soil suction range , The water-supply capacity of red soil derived from Q2 was higher than that derived from granite while In the higher soil suction range the different was not widely. As to the different mother material, The water-supply capacity of weekly erosive red-soil was the highest that of the moderate was the secondly ,that of the intensely erosive red-soil was the lowest.Available water capacity of weekly erosion red-soil derived from Qz was higher than that derived from granite. Those of moderate and intensely erosive red-soil derived from Q2 was lower than that derived from granite. As to the same mother material , the water- validity of the weekly erosive red-soil is higher than the moderate and intensely erosive red-soil.The bulk density of aggregates increased when the size of aggregates decreased while the total porosities decreased . Some special soil water content and the aerate porosities in the low suction decreased when the size of aggregates decreased.The saturated hydraulic conductivity of the red-soil derived from Q2 was lower than that of granite. The saturated hydraulic conductivity and the water diffusion rate of the weekly erosion-soil were higher than those of the moderate and intensely erosive erosion-soils. In the lower water saturatepercentage , the difference between water diffusion rate of red-soil derived from different mother material was not widely. But in the higher water saturate percentage, the water diffusion rate of red-soil derived from Q> was lower than that of granite.In the condition of simulator rainfall ,with the time goes on , the percolation rate is gradually increase .until runoff come into being , the percolation rate reach the max .After that the percolation rate is gradually decline .when the runoff rate reach the stabilization , the percolation rate reach the stabilization, in the same rainfall condition , the different of percolation rate is widely between the different erosive degree , percolation rate of the weekly erosive soil is faster than the moderate and intensely erosive soil .The cumulative percolation have the same tendency . The water content before the rainfall , the bulk density, the site of the slope , the intensity of the rainfall and the raindrop kinetic energy would effected the percolation capacity distinctly .The total water content decrease distinctively after rain and the gravitational water content and unavailable water content decrease while available water content increase , the slow available water content have not the distinctive rule. The total porosity and the aerate porosity decrease after the rain while the faster available porosity and the slow available porosity increase .Further more the saturated hydraulic conductivity decrease highly ,and the degree of decrease of the saturated hydraulic conductivity in the bottle of the slope is more than the top.更多还原